Magnon transmission across $\nu =1|-1|1$ mono-layer graphene junction as a probe of electronic structure

Abstract

We study magnon transmission across gate-controlled junctions in the $n=0$ manifold of Landau levels in monolayer graphene, in the presence of both spin and valley Zeeman fields. Specifically, we consider the $1|-1|1$ sandwich geometry. The nature of the interfaces between regions of different filling turns out to be crucial for magnon transmission. Using the Hartree-Fock approximation, we find that either the spin or the valley degrees of freedom of the occupied one-body states rotate across the interfaces. If the interfaces exhibit spin rotation, magnon transmission is suppressed at high energies, while if the interfaces have valley rotation, magnon transmission becomes perfect at high energies. The valley Zeeman coupling, which arises from partial alignment with the encapsulating Boron Nitride, is independent of perpendicular magnetic field $B$, while the spin Zeeman and other anisotropic couplings scale linearly with $B$. This allows the tuning of the relative strength of the valley Zeeman coupling in situ by varying $B$, which can drive phase transitions of the interfaces between spin-rotated and valley-rotated phases, leading to magnon transmission being either vanishing or perfect at high energies. Our analysis, along with the experimental measurements, can be used to determine the anisotropic couplings in the sample.

22 pages, 26 figures

References in corpus (30)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Ultrathin epitaxial graphite: 2D electron gas properties and a route toward graphene-based nanoelectronics
• Landau Level Splitting in Graphene in High Magnetic Fields
• Spin Filtered Edge States and Quantum Hall Effect in Graphene
• Origin of band gaps in graphene on hexagonal boron nitride
• Edge States and the Quantized Hall Effect in Graphene
• Graphene integer quantum Hall effect in the ferromagnetic and paramagnetic regimes
• Collective Modes and Skyrmion Excitations in Graphene SU(4) Quantum Hall Ferromagnets
• Evidence for a Spin Phase Transition at ν=0 in Bilayer Graphene
• Theory of integer quantum Hall effect in graphene
• Visualizing Broken Symmetry and Topological Defects in a Quantum Hall Ferromagnet
• Moiré band model and band gaps of graphene on hexagonal boron nitride
• SO(3) symmetry between Neel and ferromagnetic order parameters for graphene in a magnetic field
• Imaging tunable quantum Hall broken-symmetry orders in graphene
• Edge excitations of the canted antiferromagnetic phase of the $\nu =0$ quantum Hall state in graphene: a simplified analysis
• Conductance plateaus and shot noise in fractional quantum Hall point contacts
• Strong-Magnetic-Field Magnon Transport in Monolayer Graphene
• Full Classification of Transport on an Equilibrated 5/2 Edge via Shot Noise
• Collective Edge Modes near the onset of a graphene quantum spin Hall state
• Half-integer conductance plateau at the $\nu =2/3$ fractional quantum Hall state in a quantum point contact
• SU(4) spin waves in the $\nu =\pm 1$ quantum Hall ferromagnet in graphene
• Global phase diagram of charge neutral graphene in the quantum Hall regime for generic interactions
• Scattering of magnons at graphene quantum-Hall-magnet junctions
• Spin Mode-Switching at the Edge of a Quantum Hall System
• Distinguishing particle-hole conjugated Fractional Quantum Hall states using quantum dot mediated edge transport
• Theory of broken symmetry quantum Hall states in the $N=1$ Landau level of Graphene
• Spin-valley entangled quantum Hall states in graphene
• Emergence of spin-active channels at a quantum Hall interface
• Riemann meets Goldstone: magnon scattering off quantum Hall skyrmion crystals probes interplay of symmetry breaking and topology

Cited by in corpus (1)

• Uniquely identifying quantum Hall phases in charge neutral graphene